The present invention relates to a power steering system for a vehicle and, more particularly, to an electric powered hydraulic steering system.
A known power steering system for a vehicle has a power steering motor with an interior chamber. A rack bar for turning the steerable wheels of the vehicle extends through the interior chamber. A piston is attached to the rack bar and the piston divides the interior chamber into two variable volume chamber portions. The piston moves linearly within the interior chamber depending upon a pressure differential between the two chamber portions.
A fluid is supplied to the two chamber portions of the power steering motor from a pump. The pump is driven by an electric motor. When driven, the pump draws hydraulic fluid from a reservoir and directs the fluid to a manually actuated power steering control valve. The control valve controls the fluid flow into the chamber portions of the power steering motor.
Such a power steering system generally includes separate system components that must be individually mounted to a vehicle. The vehicle manufacturer must mount the components of the system and connect the components to form the assembled power steering system in a vehicle.
The individual components of the power steering system may include a first component comprising a power steering motor and a manually actuated control valve, and a second component that includes a reservoir and an electric motor driven pump. The two components are mounted to a vehicle, and conduits hydraulically connect the components.
The present invention is an electric powered hydraulic steering system for a vehicle. The system comprises a power steering motor having a housing with an exterior surface and an interior chamber. The power steering motor further includes a rack bar for turning the steerable wheels of the vehicle. The rack bar extends through the interior chamber of the housing. A piston is attached to the rack bar and divides the interior chamber into two chamber portions for receiving fluid. The piston moves the rack bar linearly within the interior chamber depending upon a pressure differential between the two chamber portions. The system further includes a control valve for directing the fluid into the chamber portions in the housing of the power steering motor, a pump for supplying the fluid to the control valve, a reservoir for providing the fluid to the pump, and an electric motor for driving the pump. The power steering motor, control valve, pump, reservoir, and electric motor are an integrated unit.